From 6b1ab74a9917012d0c559edc4ed299d9228ac89f Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 8 Jul 2017 08:26:47 +0200 Subject: kernel: add the new 'crashlog' feature this tries to store kernel oops/panic logs in a fixed location in RAM to recover them available to user space using debugfs Signed-off-by: Felix Fietkau --- include/linux/crashlog.h | 17 ++++ init/Kconfig | 4 + kernel/Makefile | 1 + kernel/crashlog.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ kernel/module.c | 3 + mm/bootmem.c | 2 + mm/memblock.c | 5 ++ 7 files changed, 245 insertions(+) create mode 100644 include/linux/crashlog.h create mode 100644 kernel/crashlog.c --- /dev/null +++ b/include/linux/crashlog.h @@ -0,0 +1,17 @@ +#ifndef __CRASHLOG_H +#define __CRASHLOG_H + +#ifdef CONFIG_CRASHLOG +void crashlog_init_bootmem(struct bootmem_data *bdata); +void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size); +#else +static inline void crashlog_init_bootmem(struct bootmem_data *bdata) +{ +} + +static inline void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size) +{ +} +#endif + +#endif --- a/init/Kconfig +++ b/init/Kconfig @@ -1009,6 +1009,10 @@ config RELAY If unsure, say N. +config CRASHLOG + bool "Crash logging" + depends on (!NO_BOOTMEM || HAVE_MEMBLOCK) + config BLK_DEV_INITRD bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" depends on BROKEN || !FRV --- a/kernel/Makefile +++ b/kernel/Makefile @@ -113,6 +113,7 @@ obj-$(CONFIG_CONTEXT_TRACKING) += contex obj-$(CONFIG_TORTURE_TEST) += torture.o obj-$(CONFIG_HAS_IOMEM) += memremap.o +obj-$(CONFIG_CRASHLOG) += crashlog.o $(obj)/configs.o: $(obj)/config_data.h --- /dev/null +++ b/kernel/crashlog.c @@ -0,0 +1,213 @@ +/* + * Crash information logger + * Copyright (C) 2010 Felix Fietkau + * + * Based on ramoops.c + * Copyright (C) 2010 Marco Stornelli + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CRASHLOG_PAGES 4 +#define CRASHLOG_SIZE (CRASHLOG_PAGES * PAGE_SIZE) +#define CRASHLOG_MAGIC 0xa1eedead + +/* + * Start the log at 1M before the end of RAM, as some boot loaders like + * to use the end of the RAM for stack usage and other things + * If this fails, fall back to using the last part. + */ +#define CRASHLOG_OFFSET (1024 * 1024) + +struct crashlog_data { + u32 magic; + u32 len; + u8 data[]; +}; + +static struct debugfs_blob_wrapper crashlog_blob; +static unsigned long crashlog_addr = 0; +static struct crashlog_data *crashlog_buf; +static struct kmsg_dumper dump; +static bool first = true; + +extern struct list_head *crashlog_modules; + +static bool crashlog_set_addr(phys_addr_t addr, phys_addr_t size) +{ + /* Limit to lower 64 MB to avoid highmem */ + phys_addr_t limit = 64 * 1024 * 1024; + + if (crashlog_addr) + return false; + + if (addr > limit) + return false; + + if (addr + size > limit) + size = limit - addr; + + crashlog_addr = addr; + + if (addr + size > CRASHLOG_OFFSET) + crashlog_addr += size - CRASHLOG_OFFSET; + + return true; +} + +#ifndef CONFIG_NO_BOOTMEM +void __init crashlog_init_bootmem(bootmem_data_t *bdata) +{ + phys_addr_t start, end; + + start = PFN_PHYS(bdata->node_low_pfn); + end = PFN_PHYS(bdata->node_min_pfn); + if (!crashlog_set_addr(start, end - start)) + return; + + if (reserve_bootmem(crashlog_addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) { + printk("Crashlog failed to allocate RAM at address 0x%lx\n", + crashlog_addr); + crashlog_addr = 0; + } +} +#endif + +#ifdef CONFIG_HAVE_MEMBLOCK +void __init_memblock crashlog_init_memblock(phys_addr_t addr, phys_addr_t size) +{ + if (!crashlog_set_addr(addr, size)) + return; + + if (memblock_reserve(crashlog_addr, CRASHLOG_SIZE)) { + printk("Crashlog failed to allocate RAM at address 0x%lx\n", + crashlog_addr); + crashlog_addr = 0; + } +} +#endif + +static void __init crashlog_copy(void) +{ + if (crashlog_buf->magic != CRASHLOG_MAGIC) + return; + + if (!crashlog_buf->len || crashlog_buf->len > + CRASHLOG_SIZE - sizeof(*crashlog_buf)) + return; + + crashlog_blob.size = crashlog_buf->len; + crashlog_blob.data = kmemdup(crashlog_buf->data, + crashlog_buf->len, GFP_KERNEL); + + debugfs_create_blob("crashlog", 0700, NULL, &crashlog_blob); +} + +static int get_maxlen(void) +{ + return CRASHLOG_SIZE - sizeof(*crashlog_buf) - crashlog_buf->len; +} + +static void crashlog_printf(const char *fmt, ...) +{ + va_list args; + int len = get_maxlen(); + + if (!len) + return; + + va_start(args, fmt); + crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); +} + +static void crashlog_do_dump(struct kmsg_dumper *dumper, + enum kmsg_dump_reason reason) +{ + struct timeval tv; + struct module *m; + char *buf; + size_t len; + + if (!first) + crashlog_printf("\n===================================\n"); + + do_gettimeofday(&tv); + crashlog_printf("Time: %lu.%lu\n", + (long)tv.tv_sec, (long)tv.tv_usec); + + if (first) { + crashlog_printf("Modules:"); + list_f
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -379,9 +379,18 @@ struct phy_driver {
 	 */
 	int (*config_aneg)(struct phy_device *phydev);
 
+	/* Determine if autonegotiation is done */
+	int (*aneg_done)(struct phy_device *phydev);
+
 	/* Determines the negotiated speed and duplex */
 	int (*read_status)(struct phy_device *phydev);
 
+	/* 
+	 * Update the value in phydev->link to reflect the 
+	 * current link value
+	 */
+	int (*update_link)(struct phy_device *phydev);
+
 	/* Clears any pending interrupts */
 	int (*ack_interrupt)(struct phy_device *phydev);
 
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -681,6 +681,9 @@ int genphy_update_link(struct phy_device
 {
 	int status;
 
+	if (phydev->drv->update_link)
+		return phydev->drv->update_link(phydev);
+
 	/* Do a fake read */
 	status = phy_read(phydev, MII_BMSR);
 
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -107,6 +107,9 @@ static inline int phy_aneg_done(struct p
 {
 	int retval;
 
+	if (phydev->drv->aneg_done)
+		return phydev->drv->aneg_done(phydev);
+
 	retval = phy_read(phydev, MII_BMSR);
 
 	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-30 21:41:16 +0000